180 lines · cpp
1//===- GlobalsStream.cpp - PDB Index of Symbols by Name ---------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// The on-disk structores used in this file are based on the reference10// implementation which is available at11// https://github.com/Microsoft/microsoft-pdb/blob/master/PDB/dbi/gsi.h12//13// When you are reading the reference source code, you'd find the14// information below useful.15//16// - ppdb1->m_fMinimalDbgInfo seems to be always true.17// - SMALLBUCKETS macro is defined.18//19//===----------------------------------------------------------------------===//20 21#include "llvm/DebugInfo/PDB/Native/GlobalsStream.h"22 23#include "llvm/DebugInfo/CodeView/RecordName.h"24#include "llvm/DebugInfo/MSF/MappedBlockStream.h"25#include "llvm/DebugInfo/PDB/Native/Hash.h"26#include "llvm/DebugInfo/PDB/Native/RawError.h"27#include "llvm/DebugInfo/PDB/Native/SymbolStream.h"28#include "llvm/Support/BinaryStreamReader.h"29#include "llvm/Support/Error.h"30 31using namespace llvm;32using namespace llvm::msf;33using namespace llvm::pdb;34 35GlobalsStream::GlobalsStream(std::unique_ptr<MappedBlockStream> Stream)36 : Stream(std::move(Stream)) {}37 38GlobalsStream::~GlobalsStream() = default;39 40Error GlobalsStream::reload() {41 BinaryStreamReader Reader(*Stream);42 if (auto E = GlobalsTable.read(Reader))43 return E;44 return Error::success();45}46 47std::vector<std::pair<uint32_t, codeview::CVSymbol>>48GlobalsStream::findRecordsByName(StringRef Name,49 const SymbolStream &Symbols) const {50 std::vector<std::pair<uint32_t, codeview::CVSymbol>> Result;51 52 // Hash the name to figure out which bucket this goes into.53 size_t ExpandedBucketIndex = hashStringV1(Name) % IPHR_HASH;54 int32_t CompressedBucketIndex = GlobalsTable.BucketMap[ExpandedBucketIndex];55 if (CompressedBucketIndex == -1)56 return Result;57 58 uint32_t LastBucketIndex = GlobalsTable.HashBuckets.size() - 1;59 uint32_t StartRecordIndex =60 GlobalsTable.HashBuckets[CompressedBucketIndex] / 12;61 uint32_t EndRecordIndex = 0;62 if (LLVM_LIKELY(uint32_t(CompressedBucketIndex) < LastBucketIndex)) {63 EndRecordIndex = GlobalsTable.HashBuckets[CompressedBucketIndex + 1];64 } else {65 // If this is the last bucket, it consists of all hash records until the end66 // of the HashRecords array.67 EndRecordIndex = GlobalsTable.HashRecords.size() * 12;68 }69 70 EndRecordIndex /= 12;71 72 assert(EndRecordIndex <= GlobalsTable.HashRecords.size());73 while (StartRecordIndex < EndRecordIndex) {74 PSHashRecord PSH = GlobalsTable.HashRecords[StartRecordIndex];75 uint32_t Off = PSH.Off - 1;76 codeview::CVSymbol Record = Symbols.readRecord(Off);77 if (codeview::getSymbolName(Record) == Name)78 Result.push_back(std::make_pair(Off, std::move(Record)));79 ++StartRecordIndex;80 }81 return Result;82}83 84static Error checkHashHdrVersion(const GSIHashHeader *HashHdr) {85 if (HashHdr->VerHdr != GSIHashHeader::HdrVersion)86 return make_error<RawError>(87 raw_error_code::feature_unsupported,88 "Encountered unsupported globals stream version.");89 90 return Error::success();91}92 93static Error readGSIHashHeader(const GSIHashHeader *&HashHdr,94 BinaryStreamReader &Reader) {95 if (Reader.readObject(HashHdr))96 return make_error<RawError>(raw_error_code::corrupt_file,97 "Stream does not contain a GSIHashHeader.");98 99 if (HashHdr->VerSignature != GSIHashHeader::HdrSignature)100 return make_error<RawError>(101 raw_error_code::feature_unsupported,102 "GSIHashHeader signature (0xffffffff) not found.");103 104 return Error::success();105}106 107static Error readGSIHashRecords(FixedStreamArray<PSHashRecord> &HashRecords,108 const GSIHashHeader *HashHdr,109 BinaryStreamReader &Reader) {110 if (auto EC = checkHashHdrVersion(HashHdr))111 return EC;112 113 // HashHdr->HrSize specifies the number of bytes of PSHashRecords we have.114 // Verify that we can read them all.115 if (HashHdr->HrSize % sizeof(PSHashRecord))116 return make_error<RawError>(raw_error_code::corrupt_file,117 "Invalid HR array size.");118 uint32_t NumHashRecords = HashHdr->HrSize / sizeof(PSHashRecord);119 if (auto EC = Reader.readArray(HashRecords, NumHashRecords))120 return joinErrors(std::move(EC),121 make_error<RawError>(raw_error_code::corrupt_file,122 "Error reading hash records."));123 124 return Error::success();125}126 127static Error128readGSIHashBuckets(FixedStreamArray<support::ulittle32_t> &HashBuckets,129 FixedStreamArray<support::ulittle32_t> &HashBitmap,130 const GSIHashHeader *HashHdr,131 MutableArrayRef<int32_t> BucketMap,132 BinaryStreamReader &Reader) {133 if (auto EC = checkHashHdrVersion(HashHdr))134 return EC;135 136 // Before the actual hash buckets, there is a bitmap of length determined by137 // IPHR_HASH.138 size_t BitmapSizeInBits = alignTo(IPHR_HASH + 1, 32);139 uint32_t NumBitmapEntries = BitmapSizeInBits / 32;140 if (auto EC = Reader.readArray(HashBitmap, NumBitmapEntries))141 return joinErrors(std::move(EC),142 make_error<RawError>(raw_error_code::corrupt_file,143 "Could not read a bitmap."));144 uint32_t CompressedBucketIdx = 0;145 for (uint32_t I = 0; I <= IPHR_HASH; ++I) {146 uint8_t WordIdx = I / 32;147 uint8_t BitIdx = I % 32;148 bool IsSet = HashBitmap[WordIdx] & (1U << BitIdx);149 if (IsSet) {150 BucketMap[I] = CompressedBucketIdx++;151 } else {152 BucketMap[I] = -1;153 }154 }155 156 uint32_t NumBuckets = 0;157 for (uint32_t B : HashBitmap)158 NumBuckets += llvm::popcount(B);159 160 // Hash buckets follow.161 if (auto EC = Reader.readArray(HashBuckets, NumBuckets))162 return joinErrors(std::move(EC),163 make_error<RawError>(raw_error_code::corrupt_file,164 "Hash buckets corrupted."));165 166 return Error::success();167}168 169Error GSIHashTable::read(BinaryStreamReader &Reader) {170 if (auto EC = readGSIHashHeader(HashHdr, Reader))171 return EC;172 if (auto EC = readGSIHashRecords(HashRecords, HashHdr, Reader))173 return EC;174 if (HashHdr->HrSize > 0)175 if (auto EC = readGSIHashBuckets(HashBuckets, HashBitmap, HashHdr,176 BucketMap, Reader))177 return EC;178 return Error::success();179}180